#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
	int s = 0, i = 0;;
	/*for (int i = 0; i <= 100; i += 3)
	{
		s = s + i;
	}
	printf("%d", s);*/
	while (i<=100)
	{
		if (i % 3 == 0)
		{
			s = s + i;
		}
		i++;
	}
	printf("%d",s);
	return 0;
}